Patient-specific acetabular guides and associated instruments

ABSTRACT

A method for preparing a joint surface of a patient for an implant, such as, for example, an acetabular implant for a hip joint. According to the method, a patient-specific guide is attached to a complementary joint surface of the patient. The patient-specific guide includes a guiding element oriented along a patient-specific alignment axis. The alignment axis is determined during a preoperative plan of the patient for implant alignment. A shaft of a guiding tool is removably coupled to the guiding element of the guide. A three-dimensional orientation device is removably attached to the shaft of the guiding tool. A position of a bubble of the orientation device is marked with a mark on an outer transparent surface of the orientation device while the guiding tool is oriented along the alignment axis. The marked orientation device can be used for aligning other instruments during the procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/446,660, filed on Feb. 25, 2011.

This application is a continuation-in-part of U.S. application Ser. No12/978,069 filed Dec. 23, 2010, which is a continuation-in-part of U.S.application Ser. No. 12/973,214, filed Dec. 20, 2010, which is acontinuation-in-part of U.S. application Ser. No. 12/955,361 filed Nov.29, 2010, which is a continuation-in-part of U.S. application Ser. Nos.12/938,905 and 12/938,913, both filed Nov. 3, 2010, each of which is acontinuation-in-part of U.S. application Ser. No. 12/893,306, filed Sep.29, 2010, which is continuation-in-part of U.S. application Ser. No.12/888,005, filed Sep. 22, 2010, which is a continuation-in-part of U.S.application Ser. No. 12/714,023, filed Feb. 26, 2010, which is acontinuation-in-part of U.S. application Ser. No. 12/571,969, filed Oct.1, 2009, which is a continuation-in-part of U.S. application Ser. No.12/486,992, filed Jun. 18, 2009, and is a continuation-in-part of U.S.application Ser. No. 12/389,901, filed Feb. 20, 2009, which is acontinuation-in-part of U.S. application Ser. No. 12/211,407, filed Sep.16, 2008, which is a continuation-in-part of U.S. application Ser. No.12/039,849, filed Feb. 29, 2008, which: (1) claims the benefit of U.S.Provisional Application No. 60/953,620, filed on Aug. 2, 2007, U.S.Provisional Application No. 60/947,813, filed on Jul. 3, 2007, U.S.Provisional Application No. 60/911,297, filed on Apr. 12, 2007, and U.S.Provisional Application No. 60/892,349, filed on Mar. 1, 2007; (2) is acontinuation-in-part U.S. application Ser. No. 11/756,057, filed on May31, 2007, which claims the benefit of U.S. Provisional Application No.60/812,694, filed on Jun. 9, 2006; (3) is a continuation-in-part of U.S.application Ser. No. 11/971,390, filed on Jan. 9, 2008, which is acontinuation-in-part of U.S. application Ser. No. 11/363,548, filed onFeb. 27, 2006; and (4) is a continuation-in-part of U.S. applicationSer. No. 12/025,414, filed on Feb. 4, 2008, which claims the benefit ofU.S. Provisional Application No. 60/953,637, filed on Aug. 2, 2007.

This application is continuation-in-part of U.S. application Ser. No.12/872,663, filed on Aug. 31, 2010, which claims the benefit of U.S.Provisional Application No. 61/310,752 filed on Mar. 5, 2010.

This application is a continuation-in-part of U.S. application Ser. No.12/483,807, filed on Jun. 12, 2009, which is a continuation-in-part ofU.S. application Ser. No. 12/371,096, filed on Feb. 13, 2009, which is acontinuation-in-part of U.S. application Ser. No. 12/103,824, filed onApr. 16, 2008, which claims the benefit of U.S. Provisional ApplicationNo. 60/912,178, filed on Apr. 17, 2007.

This application is also a continuation-in-part of U.S. application Ser.No. 12/103,834, filed on Apr. 16, 2008, which claims the benefit of U.S.Provisional Application No. 60/912,178, filed on Apr. 17, 2007.

The disclosures of the above applications are incorporated herein byreference.

The present teachings provide various instruments and methods forpreparing a joint surface, such as an acetabulum, for example, toreceive an implant and guiding the implant along a patient-specificalignment axis.

SUMMARY

The present teachings provide various instruments and methods forgenerally preparing a joint-surface of a patient to receive an implantalong a patient-specific alignment axis. The instruments and methods areillustrated for the acetabulum of the hip joint. The alignment axis andvarious patient-specific guides and instruments can be designed during apre-operative plan using a three-dimensional reconstruction of thepatient's relevant anatomy, such as the pelvis or portions thereof,including the acetabular and periacetabular areas of the pelvis. Thethree-dimensional reconstruction can be based on two-dimensional medicalimages, including MRI, CT or X-ray scans and prepared using commerciallyavailable imaging software.

In some embodiments, the present teachings provide a method forpreparing a joint surface of a patient for an implant, such as, forexample, an acetabular implant for a hip joint. According to the method,a patient-specific guide is attached to a complementary joint surface ofthe patient. The patient-specific guide includes a guiding elementoriented along a patient-specific alignment axis. The alignment axis isdetermined during a preoperative plan of the patient for implantalignment. A shaft of a guiding tool is removably coupled to the guidingelement of the guide. A three-dimensional orientation device isremovably attached and can be keyed to the shaft of the guiding tool. Aposition of a bubble of the orientation device is marked with a mark onan outer transparent surface of the orientation device while the guidingtool is oriented along the alignment axis. In some embodiments, theguiding tool can be an acetabular inserter fitted with a removableadapter tip.

The orientation device, as marked, can be used for aligning otherinstruments during the procedure. For example, the orientation devicecan be used with a shaft of a reamer to align the reamer along thealignment axis. The orientation device can also be used with a shaft ofan acetabular inserter of an implant for inserting and implanting theimplant into the joint. A number of orientation devices can be providedin a surgical kit including one or more patient-specific guides, modularhandles, tools and shafts, reamer or other cutting tools, inserters orimplant impactors. The surgical kit can also include one or more implantcomponents. The orientation devices can be reusable or disposable.

The acetabular guide can be provided in various fitment options in whichthe patient-specific engagement surface includes additional portionscomplementary to a portion of the acetabular rim and/or a portion of thetransverse acetabular ligament.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIGS. 1-5 illustrate environmental perspective views of variouspatient-specific acetabular alignment guides according to the presentteachings;

FIG. 6 is an environmental perspective view of various instrumentsillustrating a method for establishing an acetabular cup insertion axisaccording to the present teachings;

FIG. 7 is an environmental perspective view illustrating drilling apilot hole for guided reaming according to the present teachings;

FIG. 8A is an environmental perspective view illustrating a reamer forguided reaming according to the present teachings;

FIG. 8B is a stylized perspective view of a reamer for guided reamingaccording to the present teachings;

FIG. 8C is a partially sectioned perspective view of the reamer of FIG.8B;

FIG. 9 is an environmental perspective view illustrating instruments forcup insertion according to the present teachings;

FIG. 10 is an environmental perspective view of a patient-specificacetabular alignment guide with alignment pins for a secondary guideaccording to the present teachings;

FIG. 11 is an environmental perspective view of another patient-specificacetabular alignment guide with alignment pins for a secondary guideaccording to the present teachings;

FIG. 12 is an environmental perspective view of the patient-specificacetabular alignment guide of FIG. 10 illustrating drilling a pilot holefor guided reaming according to the present teachings;

FIG. 13 is an environmental perspective view of a secondary guide overthe alignment pins of FIG. 10 according to the present teachings;

FIG. 14 is an environmental perspective view illustrating a method forestablishing an acetabular cup insertion axis using an orientationdevice according to the present teachings;

FIG. 15A is a perspective view of the orientation device of FIG. 14;

FIG. 15B is a plan view of the orientation device of FIG. 14;

FIG. 16 is an environmental perspective view illustrating a method forinserting an acetabular cup using the orientation device of FIG. 15Aaccording the present teachings; and

FIG. 17 is an environmental perspective view illustrating a method forpreparing an acetabulum using the orientation device of FIG. 15Aaccording the present teachings.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses.

The present teachings generally provide various patient-specificacetabular alignment guides, secondary guides, reamers, inserters,impactors and other associated instruments for use in orthopedicsurgery, such as in joint replacement or revision surgery, for example.The patient-specific alignment guides and associated instruments can beused either with conventional or with patient-specific implantcomponents prepared with computer-assisted image methods.

As described in commonly assigned U.S. application Ser. No. 11/756,057,filed on May 31, 2007, during a preoperative planning stage, imagingdata of the relevant anatomy of a patient can be obtained at a medicalfacility or doctor's office. The imaging data can include, for example,a detailed scan of a pelvis, hip, knee, ankle or other joint or relevantportion of the patient's anatomy. The imaging data can be obtained usingan MRI, CT, X-Ray, ultrasound or any other imaging system. The imagingdata obtained can be used to construct a three-dimensional computerimage of the joint or other portion of the anatomy of the patient andprepare an initial pre-operative plan that can include bone or jointpreparation, including planning for resections, milling, reaming,broaching, implant selection and fitting, design of patient-specificguides, templates, tools and alignment protocols for the surgicalprocedure.

Computer modeling for obtaining three-dimensional computer images of therelevant patient's anatomy can be provided by various CAD programsand/or software available from various vendors or developers, such as,for example, from Materialise USA, Plymouth, Mich. The computer modelingprogram can be configured and used to plan a preoperative surgical plan,including planning various bone preparation procedures, to select ordesign/modify implants and design patient-specific guides and tools. Thepatient-specific components include patient-specific implants, andpatient-specific tools, including reaming, broaching, milling, drillingor cutting tools, alignment guides, templates and other patient-specificinstruments.

The pre-operative plan can be stored in any computer storage medium, ina computer file form or any other computer or digital representation.The pre-operative plan, in a digital form associated with interactivesoftware, can be made available via a hard medium, a web-based or mobileor cloud service, or a cellular portable device to the surgeon or othermedical practitioner, for review. Using the interactive software, thesurgeon can review the plan, and manipulate the position of images ofvarious implant components relative to an image of the anatomy. Thesurgeon can modify the plan and send it to the manufacturer withrecommendations or changes. The interactive review process can berepeated until a final, approved plan, is sent to a manufacturingfacility for preparing the actual physical components.

After the surgical plan is approved by the surgeon, patient-specificimplants and associated tools, including, for example, alignment guides,cutting/milling/reaming/broaching or other tools for the surgicalpreparation of the joint or other anatomy portion of the specificpatient can be designed using a CAD program or other three-dimensionalmodeling software, such as the software provided by Materialise, forexample, according to the preoperative surgical plan. Patient-specificguides and other instruments can be manufactured by variousstereolithography methods, selective laser sintering, fused depositionmodeling or other rapid prototyping methods. In some embodiments,computer instructions of tool paths for machining the patient-specificguides and/or implants can be generated and stored in a tool path datafile. The tool path data can be provided as input to a CNC mill or otherautomated machining system, and the tools and implants can be machinedfrom polymer, ceramic, metal or other suitable material depending on theuse, and sterilized. The sterilized tools and implants can be shipped tothe surgeon or medical facility for use during the surgical procedure.

Patient-specific implants, guides, templates, tools or portions thereofare defined herein as those constructed by a surgical plan approved bythe surgeon using thee-dimensional images of the specific patient'sanatomy and made to closely conform and mate substantially as a negativemold of corresponding portions of the patient's anatomy, including bonesurfaces with or without associated soft tissue, such as articularcartilage, for example, depending on the particular procedure, implantand tool use.

Patient-specific alignment guides and implants are generally configuredto match the anatomy of a specific patient. The patient-specificalignment guides are generally formed using computer modeling based onthe patient's 3-D anatomic image and have an engagement surface that ismade to conformingly contact and match a three-dimensional image/modelof the patient's bone surface (with or without cartilage or other softtissue), by the computer methods discussed above. The patient-specificalignment guides can include custom-made guiding formations, such as,for example, guiding bores or cannulated guiding posts or cannulatedguiding extensions or receptacles that can be used for supporting orguiding other instruments, such as drill guides, reamers, cutters,cutting guides and cutting blocks or for inserting pins or otherfasteners according to a surgeon-approved pre-operative plan. Thepatient-specific alignment guides can be used in minimally invasivesurgery, and also in surgery with multiple minimally-invasive incisions.Various alignment guides and pre-operative planning procedures aredisclosed in commonly assigned and co-pending U.S. patent applicationSer. No. 11/756,057, filed on May 31, 2007; U.S. patent Application Ser.No. 12/211,407, filed Sep. 16, 2008; U.S. patent application Ser. No.11/971,390, filed on Jan. 9, 2008, U.S. patent application Ser. No.11/363,548, filed on Feb. 27, 2006; and U.S. patent application Ser. No.12/025,414, filed Feb. 4, 2008. The disclosures of the aboveapplications are incorporated herein by reference.

Referring to FIGS. 1-5, the present teachings provide variouspatient-specific acetabular guides 100, 200. The acetabular guides 100,200 can be used in connection with various other instruments tofacilitate guided reaming of an acetabulum 82 of a pelvis 80 of aspecific patient and guided insertion and implantation of an acetabularimplant or acetabular cup in the acetabulum 82. Further, thepatient-specific acetabular guides 100, 200 engage the acetabulum 82 ofthe specific patient in a unique (only one) position and can provide anaccurate alignment axis relative to the planned orientation of theacetabular cup 280 (shown in FIG. 9, for example). The patient-specificacetabular guides 100, 200 can also provide secure fitting androtational stability in a design that is lightweight with minimal sizeand bulk.

FIGS. 1-3 illustrate a patient-specific acetabular guide 100 having apatient-specific body 102, as described below, and a guiding or pilotelement 104 having an elongated bore 106 with a patient-specificalignment axis A. The alignment axis A is configured to be central tothe acetabular cup and perpendicular to the acetabular cup's surfacewhen the acetabular guide 100 is positioned on the acetabulum 82. Theacetabular guide 100 can be provided in various fitment optionsdepending on the planned exposure of the acetabulum 82 for the reamingprocedure and implantation. Each fitment option of the acetabular guide100 can include a portion that covers the acetabular fossa at the centerof the acetabulum 82, which provides a landmark for rotational stabilityand unique positioning on the acetabulum. Each fitment option caninclude additional portions complementary to a portion of the acetabularrim 84 and/or a portion of the transverse acetabular ligament 83, asdiscussed below in further detail. Each fitment option allows theacetabular guide 100 to have a compact size, extend through the centerof the acetabulum 82 for alignment, and include portions that can fitover various anatomic landmarks in a unique position for the patient.The particular fitment option can be selected for each specific patientbased on the patient's anatomy, the procedure to be performed and thesurgeon's preference and/or technique.

Three exemplary fitment options designated 100A, 100B and 100C areillustrated in FIGS. 1-3, respectively. The fitment options can includefitments engaging or registering to various combinations of portions ofthe acetabulum 82, the acetabular rim 84 and the transverse acetabularligament 83. For example, the acetabular guide 100 in the fitment option100A may engage portions of the acetabulum 82, the acetabular rim 84 andthe transverse acetabular ligament 83. In the fitment option 1008, theacetabular guide 100 may engage portions of the acetabulum 82 and theacetabular rim 84. In the fitment option 100C, the acetabular guide 100may engage portions of the acetabulum 82 and the transverse acetabularligament 83. Either one or several acetabular guides (or fitmentoptions) 100A, 100B, 100C corresponding to different fitment options canbe provided to the surgeon for intra-operative flexibility and planchange, according to the surgeon's preference. The acetabular guide 100can be secured to the patient's bone with bone pins, guide wires orother fasteners.

The patient-specific body 102 of the acetabular guide 100 can include aninner portion 102 a (all fitment options) from which the guiding elementextends and which is designed to engage the acetabulum 82, an outerportion 102 b which extends from the inner portion 102 a and isconfigured to extend over a portion of the rim 84 (for fitment options100A and 100C) and an outer portion 102 c (fitment options 100A and100C) configured to extend over a portion of the transverse acetabularligament 83 (and adjacent area of the acetabulum 82). The patientspecific body 102 has an underside three-dimensional engagement surface108 that is custom-made or patient-specific to conform to and mirrorcomplementary surfaces of various combinations of the acetabulum 82, rim84 and/or transverse acetabular ligament 83 or other periacetabularsurfaces of the pelvis 80 of the specific patient, as described above inconnection with the various fitment options. The patient specific body102 is designed by using a three-dimensional image or model of theacetabulum 82 and surrounding pelvic area of the patient, as describedabove. The engagement surface 108 enables the acetabular guide 100 tonest or closely mate relative to the complementarily acetabular surfaceof the patient. The acetabular guide 100 can be designed to havegenerally small thickness, such that it can form a lightweightthree-dimensional shell from which the guiding element 104 extendsopposite to the engagement surface. The guiding element 104 can beformed to be a monolithic or integral portion of the acetabular guide100. Alternatively, the guiding element 104 can be modularly andremovably coupled to the acetabular guide 100, using, for example, athreaded connection, snap-on connectors or other removable attachments.

Referring to FIGS. 4 and 5, another patient-specific acetabular guide200 is illustrated with two exemplary fitment options 200A and 200B.Similarly to the acetabular guide 100, the acetabular guide 200 alsoincludes a patient-specific body 202 and a guiding or pilot element 204having an elongated bore 206 with an alignment axis A configured to becentral to the acetabular cup and perpendicular to the acetabular cup'ssurface when the acetabular guide 200 is positioned on the acetabulum82. The acetabular guide 200 can include one or more marker elements 250(two are shown in the exemplary embodiments of FIGS. 4 and 5), eachhaving an elongated bore 252 for guiding marker pins 260. The markerpins 260 can be used for supporting a secondary guide for anotherpreparation method discussed below in reference to FIG. 12. The otherfeatures of the acetabular guide 200 are similar to that of theacetabular guide 100, such that the acetabular guide 200 can also beused instead of the acetabular guide 100. The acetabular guide 100 canbe used for procedures in which the marker elements 250 are notutilized, as described below. The acetabular guide 200 can be used forprocedures in which the marker elements 250 may or may not be utilized,as described below.

The patient-specific body 202 of the acetabular guide 200 is generallysimilar to patient-specific body 102 of the acetabular guide 100, suchthat the patient-specific body 202 can include an inner portion 202 afrom which the guiding element extends and which is designed to engagethe acetabulum 82, and an outer portion 202 b which extends from theinner portion 202 a and is configured to extend over a rim portion 84 ofthe acetabulum 82. The outer portion 202 b extends sufficiently beyondthe rim 84 to the periacetabular area of the pelvis to accommodate themarker elements 250. The patient specific body 202 has an undersidebone-engaging three-dimensional engagement surface 208 that iscustom-made or patient-specific to conform and mirror in complementarysurfaces of the acetabulum 82, rim 84 (with or without the transverseacetabular ligament 83) or other periacetabular surfaces of the pelvis80 of the specific patient by using a three-dimensional image or modelof the acetabulum and surrounding pelvic area of the patient, asdescribed above. The engagement surface 208 enables the acetabular guide100 to nest or closely mate relative to the complementarily acetabularsurface of the patient. The acetabular guide 200 can be designed to havegenerally small thickness, such that it can form a lightweightthree-dimensional shell from which the guiding element 204 and markerelements 250 extend.

Referring to FIGS. 6-9, a method for reaming and preparing theacetabulum for an implant is described in connection with thepatient-specific acetabular guides 100. The acetabular guides 200 canalso be used, although the marker elements 250 are not utilized in thismethod. Referring to FIG. 6, a patient-specific acetabular guide 100 (or200) is placed in a unique position on the acetabulum/rim/transverseacetabular ligament depending on the fitment option, as determined inthe preoperative plan for the specific patient, and establishes thealignment axis A along the guiding element 104. An elongated guidingtool 300, such as a guiding handle 300 can be attached to the guidingelement 104 such that the center axis of the guiding handle 300coincides with the alignment axis A. The guiding handle 300 can includea proximal gripping portion 302, an elongated shaft 304 extending fromthe gripping portion 302 and a coupling distal portion or removableadapter tip 306 which can be removably coupled to the guiding element104 such that the guiding handle 300 is aligned along the alignment axisA. The distal portion 306 can include, for example, a bore 308 forreceiving the guiding element 104. The guiding element 104 and the bore308 can be of sufficient length for the guiding handle 300 to beremovably yet stably coupled to the guiding element 104 for indicatingthe alignment axis A without wobbling or other misaligning motion. Theguiding tool 300 can also be an acetabular cup inserter, such as theinserter 550 illustrated in FIGS. 9 and 16, which can be fitted with theremovable adapter tip 306 for removably connecting to the guidingelement 104.

With continuing reference to FIG. 6, a support device or jig oroutrigger 400 can be secured on the pelvis 80. The support device 400can be used to orient an alignment pin or rod 402 along an axis A′parallel to the alignment axis A. More specifically, the support device400 can include a universal rotational adjustment mechanism 406 and apivotable/translational adjustment mechanism 408 for removably engagingthe shaft 304 and aligning the alignment rod 402 parallel to the shaft304 and, therefore, parallel to the alignment axis. In the exemplaryembodiment of FIG. 6, the support device 400 can include a leg 410 thatcan be attached to the bone with a bone fastener through a hole 412 at afoot or base 414 of the leg 410. The support device 400 can also includean arm 416 that is slidably coupled to the leg 410 to allow fortranslational motion of the arm 416 relative to the leg 410. The arm 416can have, for example, an elongated slot 418 that slidably receives afastener head 420 of a fastener 422, such as a screw or bolt that isreceived through a distal flange 424 of the leg 410. The flange 424 canalso pivot relative to the arm 416 about an axis B along the axis of theleg 410 and fastener 422. The head 420 of the fastener 422 can berotated to lock the flange 424 and the leg 410 relative to the arm 416.The interconnection of the arm 416, the leg 410 and the fastener 422collectively form the pivotable/translational adjustment mechanism 408.

With continued reference to FIG. 6, the arm 416 can be substantiallyplanar and include at a distal end a housing 426 forming a socket 428for a ball 430 at a distal end of a connector 432. The socket 428 andthe ball 430 form a universal (ball) joint of the universal rotationaladjustment mechanism 406 for rotationally adjusting the connector 432relative to the arm 416. After adjustment, the orientation of theconnector 432 can be locked with a fastener 436 through the housing 426.The connector 432 supports the alignment rod 402 and includes anengagement surface 434 that can engage the shaft 304, by a snap-on orother quick connect/disconnect connection. The support device 400 can beadjusted using the adjustment mechanisms 406, 408 described above suchthat the alignment rod 402 along axis A′ is parallel to the alignmentaxis A of the shaft 304. In other words, the alignment rod 402 can serveas a marker for the orientation of the alignment axis A to guide reamingand cup insertion procedures as discussed below.

After the support device 400 is locked in a position such that theorientation of the alignment rod 402 along axis A′ is fixed and parallelto the alignment axis A, the guiding handle 300 (or the acetabularinserter 550) is disengaged from the engagement surface 434 of theconnector 432 and the acetabular guide 100 and is removed. Referring toFIG. 7, a drilling element 440 can be guided through the bore 106 of theguiding element 104 of the acetabular guide 100 to drill a pilot hole 89in the acetabulum 82 along the alignment axis A, as shown in FIG. 8A.The drilling element 440 can include a stop 442 at a pre-determinedposition to prevent over drilling or drilling through the wall of theacetabulum 82. The depth of drilling and the location of the stop 442 onthe drilling element 440 can be determined during the pre-operative planfor the specific patient. The support device 400 and alignment rod 402remain attached to the pelvis as shown in FIG. 6, although not fullyshown in FIG. 7. After the pilot hole 89 is drilled, the acetabularguide 100 is removed.

Referring to FIG. 8A, a reamer 500 can be guided along the alignmentaxis A to ream the acetabulum 82. Another embodiment of a reamer 500′according to the present teachings is illustrated in FIGS. 8B and 8C.The reamers 500 and 500′ can be used interchangeably and similarelements will be referenced with the same numerals herein below. Thereamer 500 (500′) can include a trocar or other guiding pin 502 that issized to fit and be received in the pilot hole 89 of the acetabulum 82for stabilizing and guiding the reamer 500 (500′) along the alignmentaxis A, i.e., at a predetermined location and orientation. This guidedreaming arrangement enables the surgeon to recreate the preoperativeplanned position and orientation for reaming the acetabulum 82 andimplanting the acetabular component. The alignment rod 402 which issupported by the support device 400 along the axis A′ that is parallelto the alignment axis A can also help to guide the reamer 500 (500′).

The reamer 500 (500′) can include a plurality of curved reaming blades504 and a supporting shaft 506 for a reamer driver or reamer handle. Thecurved blades 504 can be attached to a plurality of curved supportingelements 508 in the form of spherical leaves or sphericalsection/portions that collectively define a semi-spherical surfacecorresponding to the shape and size of the acetabular component to beimplanted in the acetabulum after reaming. The blades 504 can beremovable and replaceable or disposable. The entire reamer head thatincludes the blades 504 and the support element 508 can also bedisposable. A reamer 500 with four disposable blades 504 is illustratedin FIG. 8A, while the reamer 500′ shown in FIGS. 8B and 8C includes onlytwo reamer blades 504. Referring to FIG. 8C, the guiding pin 502 can bespring biased to provide a tactile feedback during reaming. A spring orother biasing element 510 can be constrained between a proximal end 512of the guiding pin 502 and a wall 514 of the supporting shaft 506. A setscrew or fastener 516 can be used to stabilize the guiding pin 502 whileallowing slidable movement along the alignment axis during reaming. Thespring 510 can surround the fastener 516, as shown in FIG. 8C.Specifically, the fastener 516 is threaded to a blind bore 503 of theguiding pin 502 such that the fastener 516 and the guiding pin can movetogether along the alignment axis A by or against the action of thespring 510. The embodiments of FIGS. 8B and 8C also include a base ring518 integrally attached to the shaft 506 providing additional stability.

Referring to FIG. 9, after the acetabulum 82 has been reamed anacetabular inserter 550 can be coupled to an acetabular cup 280 by anend coupler 552 at the distal end of a shaft 554 of the acetabularinserter 550. The end coupler 552 can be removable. As seen in FIG. 9,the shaft 554 can be slidably and removably coupled to the engagementsurface 434 of the connector 432 of the support device 400, such thatthe shaft is oriented along the alignment axis A for insertion of theacetabular cup 280 according to the preoperatively planned position andorientation.

Referring to FIGS. 10-13, another method of reaming and preparing theacetabulum 82 is illustrated using the acetabular guides 200 withfitment options 200A and 200B, as described above in connection withFIGS. 4 and 5. In this method, marker pins 260 are inserted through thecorresponding bores 252 of the marker elements 250 and attached to thebone in locations and orientations parallel to an axis B, as determinedduring the preoperative plan. The marker pins 260 can guide the locationof a secondary guide 600, shown in FIG. 13, which is designed accordingto the pre-operative plan to be guided by the marker pins 260, asdiscussed below.

As was described above in connection with FIG. 7 and the acetabularguides 100, a pilot hole 89 is drilled into the acetabulum 82 throughthe guiding element 204 with a drilling element 440 until the stop 442of the drilling element 440 reached the upper surface of the guidingelement 204 of the acetabular guide 200. The acetabular guide 200 can beslidably lifted off the marker pins 260 and removed, leaving the markerpins 260 attached to the bone. A reamer 500, 500′ with a guiding pin 502can be used to ream the acetabulum 82, as discussed above in connectionwith FIG. 7. The acetabular cup 280 can be inserted using an acetabularinserter 550 without the aid of an alignment orientation, although asupport device 400 with an alignment rod 402 can also be used ifdesired.

After the acetabular cup 280 is inserted but not impacted, a secondaryguide 600 having guiding elements 650 with bores 652 complementarilycorresponding to the orientation and relative location of the markerelements 250 of the acetabular guide 200 is placed over the marker pins260. The secondary guide 600 can be designed during the pre-operativeplan such that the bores 652 are complementary to the location andorientation of the marker elements 250 of the acetabular guide. Thesecondary guide 600 can include extender elements 604 supporting anarcuate or crescent-shaped planar flange 602 having parallel inferiorand superior surfaces 608, 610 designed during the pre-operative plan tobe oriented parallel to a rim 282 of the acetabular cup 280, when theacetabular cup 280 is positioned in the predetermined position andorientation. The orientation and position of the acetabular cup 280 isadjusted using the secondary guide 600, such that the planar flange 602(and the inferior and superior surfaces 608, 610 of the planar flange602) and the rim 282 are parallel. It is noted that this method does notmake use of the support device 400, although the acetabular guides 200can also be used with the supporting device, at the discretion of thesurgeon. Depending on the surgeon's preferences, any selected or all theacetabular guides 100 (110A, 100B, 100C) and 200 (200A, 200B) and theassociated instruments including the reamer 500, 500′, the supportingdevice 400, the drilling element 440 with the stop 442, alignment rod402, marker pins 260 and the secondary guide 600 can be provided in asurgical kit together with the acetabular cup 280 and/or additionalimplants and instruments.

Referring to FIGS. 15A and 15B, an orientation device 800 can be used toestablish the alignment axis A for preparing a joint surface with acutting tool and inserting an implant along the alignment axis. Thecutting tool can be a milling, reaming, resurfacing, burring, sawing orany other tool for preparing the joint surface of the patient. The jointcan be a hip, knee, elbow, shoulder or other joint surface.

Referring to FIGS. 14-17, the orientation device 800 is illustrating inexemplary procedures for reaming the acetabulum 82 and inserting anacetabular cup 280. The orientation device 800 can be designed toindicate whether an axis of a shaft (304, 554, 555) or otherlongitudinal member of an instrument to be in preparation of the jointsurface and/or insertion of the implant is aligned along a predeterminedand patient-specific orientation when the orientation device 800 isattached to the longitudinal member. The longitudinal member can be ashaft of any surgical instrument including, for example,cutting/milling/reaming/burring tools, implant inserters and impactors.The orientation device 800 can also be attached any shaft that can beremovably coupled to a modular tool. In the exemplary embodimentsillustrating the use of the orientation device 800 for an acetabularjoint surface, the longitudinal member can be the shaft 304 of theguiding handle 300 (FIG. 6, FIG. 14), the shaft 554 of the inserter 550(FIG. 9, FIG. 16) or a shaft 555 coupled to a reamer 500 (FIG. 17). Theshafts 304, 554 and 555 can be removably coupled to the respectiveinstruments. In some embodiments, a single (the same) shaft can be usedfor more than one instrument.

Referring to FIGS. 15A and 15B, the orientation device 800 can be athree-dimensional leveling device having a three-dimensional orientationcapability. For example, the orientation device 800 can include atransparent dome-shaped surface 808, such as a portion of a sphere or ahemi-sphere or a dome, attached to a planar base 803. The volume betweenthe surface 808 and the planar surface can be filled with a liquidhaving a single air bubble or leveling bubble 802 to act as anorientation indicator. The shape of the orientation device 800 allowsthe bubble 802 to move in three-dimensional space indicating anorientation in three-dimensions relative to the base 803 and is athree-dimensional symmetric surface, such as a hemispherical surface. Acoupler 804 can extend from the base 803 for removably coupling theorientation device to a shaft. The coupler 804 can include, for example,a snap-on groove 806 configured to removably attach to any one of theshafts 304, 554 and 555 as discussed above. The coupler 804 can be keyedto the shaft with a tongue-in-groove or other keying device. The keyingdevice can include a first key component 811 on the coupler 803 and asecond key component 311 on shaft 304 (511 on shafts 554 and 555) matingwith the first key component 811. The first key component 811 can be anextension or tab or key and the second key component 311 or 511 can be amating slot or channel or groove, or the other way around. The coupler804 can be integrally or removably coupled to base 803. The coupler 804can be attached to the base with adhesive, hoop-and-loop material,respective tongue-and-groove or deflectable snap-on elements or otherconnections. In some embodiments, the coupler 804 can be attachable toshafts with variable size diameters. Alternatively, a variety ofremovable couplers 804 having grooves 806 with different sizes can beprovided for coupling to shafts of different diameters.

The orientation device 800 can be calibrated using one of the patientspecific acetabular guides 100 or 200, in any fitment option. Referringto FIG. 14, for example, a patient-specific acetabular guide ispositioned in a unique location on the patient's acetabulum 82. Theguiding element 104 of the acetabular guide 100 is oriented along thepre-operatively determined patient-specific alignment axis A, asdiscussed above in connection with FIGS. 1-5, for example. The guidinghandle 300 (or the acetabular inserter 550 with the adapter tip 306, asdiscussed above) with the orientation device 800 keyed thereon iscoupled and keyed to the guiding element 104 and the shaft 304 of theguiding handle 300 (or the acetabular inserter 550 with the adapter tip306, as discussed above) becomes oriented along the same alignment axisA, as discussed above, in connection with FIG. 4. While the shaft 304 isoriented along the alignment axis A, the position of the bubble 802 ismarked using a marker, pencil or other marking instrument with a mark801, which can be, for example a dot at its center or a circlesurrounding and centered about the bubble 802. When the orientationdevice 800 is subsequently attached and keyed to another shaft, thatshaft can be aligned along the alignment axis A by ensuring that thebubble 802 aligns and is centered relative to the mark 801, as discussedbelow. Referring to FIGS. 16 and 17, the orientation device 800, can beused to align the shaft 554 of the inserter 550 and/or the shaft 555 ofa reamer 500.

The orientation device 800 can be used with any of the methods discussedfor preparing the acetabulum as an additional redundant alignmentdevice, or with the following method. The orientation device 800 isfirst calibrated intra-operatively as discussed above in connection withFIG. 14. Specifically, the pre-selected patient-specific guide 100 isattached in a pre-operatively determined unique location relative to theacetabulum 82 of the specific patient. In this position, the guidingelement 104 of the acetabular axis is oriented along the pre-operativelydetermined alignment axis A. The guiding handle 300 (or the acetabularinserter 550 with the adapter tip 306, as discussed above) with theorientation device 800 coupled and keyed thereon can be coupled to theacetabular guide 100 such that the guiding element 104 is received andkeyed in the bore 308 of the distal portion 306 of the guiding handle300 (or the acetabular inserter 550 with the adapter tip 306, asdiscussed above), thereby aligning the shaft 304 of the guiding handle300 along the alignment axis A. The position of the bubble 802 relativeto the base 803 is noted and a mark 801 is placed on the surface 808centered relative to the bubble. The mark 801 can be made with a markeror other writing or marking instrument.

The guiding handle 300 (or the acetabular inserter 550 with the adaptertip 306, as discussed above) is removed from the acetabular guide 100.If a guiding handle 300 was used, then the orientation device 800 isremoved from the guiding handle 300. If the acetabular inserter with theadapter tip 306 was used, then the orientation device 800 remains on theacetabular inserter 550, but the adapter tip 306 is removed and replacedwith the end coupler 552, shown in FIG. 16. The acetabular guide 100 canbe optionally used to drill a pilot hole 89 in the acetabulum 82, asdiscussed above, for example in connection with FIG. 7. Otherwise, theacetabular guide 100 is removed from the patient without drilling apilot hole 89. A reamer, such as the reamer 500 discussed above inconnection with FIG. 8A, for example, or other reamer can be used theream the acetabulum 82 along the alignment axis A. More specifically,and referring to FIG. 17, a driver handle having a shaft 555 is coupledto the reamer 500. The orientation device 800 is connected to the shaft555. The orientation of the shaft 555 is adjusted such that theorientation device 800 indicates alignment along the alignment axis A,i.e., the bubble 802 is centered relative to the mark 801. After reamingthe acetabulum 82, the orientation device 800 can be attached to theshaft 554 of the inserter 500 for inserting the acetabular implant 280into the prepared acetabulum 82, as shown in FIG. 16.

Although the orientation device 800 was described above in connectionwith an acetabular joint, the orientation device 800 can be usedconveniently for aligning a variety of surgical instruments used duringthe preparation of any joint surface of a patient for receiving animplant in orthopedic surgery. It can provide alignment accuracy whencalibrated with patient-specific guides that include guiding elementsdesigned during a pre-operative plan for a specific patient. Severaldisposable or reusable orientation devices 800 with variouspatient-specific guides and guiding handles or modular shafts can beincluded in a surgical kit for a specific patient. For example, a numberof orientation devices 800 can be included in a kit with one or moreacetabular guides 100, 200 and other instruments that can be modularlycoupled to the guiding elements 104, 204 of the acetabular guides for anacetabular joint replacement procedure. Guiding handles or other modularshafts, as well as reamers, inserters and other instruments and/orimplant can also be included in the surgical kit. Marking instruments,such as off-the-shelf markers, disposable or other sterilizable markerscan also be included. Implant components for the specific patient canalso be included in the surgical kit.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the present teachings without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

1. A method for preparing an acetabulum of a patient for an acetabularimplant, the method comprising: removably engaging an acetabular area ofthe patient to a complementary surface of a patient-specific acetabularguide, the acetabular guide having a guiding element oriented along apatient-specific alignment axis, the alignment axis determined during apreoperative plan of the patient for implant alignment; removablycoupling a shaft of a guiding tool to the guiding element of theacetabular guide such that the shaft of the guiding tool is orientedalong the alignment axis; removably attaching a three dimensionalorientation device to the shaft of the guiding tool; calibrating theorientation device to indicate the alignment axis orientation; removingthe acetabular guide and guiding tool; removing the orientation devicefrom the guiding tool; removably attaching the orientation device to ashaft of an instrument; and guiding the shaft of the instrument alongthe alignment axis using the orientation device.
 2. The method of claim1, wherein the instrument is a reamer and further comprising reaming theacetabulum with the reamer.
 3. The method of claim 2, furthercomprising: removing the orientation device from the shaft of thereamer; removably attaching the orientation device to a shaft of aninserter coupled to an acetabular cup; guiding the shaft of the inserteralong the alignment axis using the orientation device; and inserting theacetabular cup in the acetabulum.
 4. The method of claim 2, furthercomprising: drilling a pilot hole in the acetabulum through a bore ofthe guiding element; and guiding an alignment pin of the reamer in thepilot hole.
 5. The method of claim 4, wherein drilling a pilot hole inthe acetabulum through a bore of the guiding element includes using adrilling element having a stop at a predetermined position forpreventing over drilling of the acetabulum.
 6. The method of claim 1,wherein calibrating the orientation device to indicate the alignmentaxis orientation comprises marking a position of a bubble inside theorientation device, the bubble viewable through an outer transparentsurface of the orientation device.
 7. The method of claim 1, furthercomprising keying the orientation device to the shaft of the instrument.8. The method of claim 1, wherein the guiding tool is a guiding handle.9. The method of claim 1, wherein the guiding tool is an acetabularinserter with a removable adapter tip couplable to the guiding elementof the patient-specific acetabular guide.
 10. A method for preparing ajoint surface of a patient for an implant, the method comprising:attaching a patient-specific guide to a complementary joint surface ofthe patient, the patient-specific guide having a guiding elementoriented along a patient-specific alignment axis, the alignment axisdetermined during a preoperative plan of the patient for implantalignment; removably coupling a shaft of a guiding tool to the guidingelement of the patient-specific guide; removably attaching athree-dimensional orientation device to the shaft of the guiding tool;and marking a position of a bubble of the orientation device with a markon an outer transparent surface of the orientation device while theguiding tool is oriented along the alignment axis.
 11. The method ofclaim 10, further comprising: removing the orientation device from theguiding tool for use intra-operatively with other instruments andpreparing the joint surface.
 12. The method of claim 11, furthercomprising: removing the patient-specific guide and the guiding tool;removably attaching the orientation device to a reamer; aligning thereamer along the alignment axis using the orientation device; andreaming the joint surface.
 13. The method of claim 11, furthercomprising: removably keying and attaching the orientation device to ashaft of a cutting tool; aligning the shaft of the cutting tool alongthe alignment axis using the orientation device; and preparing the jointsurface with the cutting tool.
 14. The method of claim 10, furthercomprising: removably keying and attaching the orientation device to ashaft of an inserter holding an implant for the joint surface; aligningthe shaft of the inserter along the alignment axis using the orientationdevice; and inserting the implant in the joint surface.
 15. The methodof claim 10, wherein the guiding tool is an acetabular inserter with anadapter tip couplable to the guiding element of the patient-specificguide and further comprising: aligning the shaft of the acetabularinserter along the alignment axis using the orientation device; andinserting the implant in the joint surface.
 16. A surgical kit forpreparing a joint surface to receive an implant, the surgical kitcomprising: a patient-specific guide for a joint surface, thepatient-specific guide having a patient-specific surface complementaryto a surface of the joint for nesting engagement and a guiding elementoriented along a patient-specific alignment axis, the alignment axisdetermined during a preoperative plan of the specific patient forimplant alignment; a guiding tool couplable to the guiding element ofthe patient-specific guide; and a three-dimensional orientation deviceremovably couplable the guiding tool for intra-operative calibration,such that, after calibration, the orientation device can be removablycoupled to a shaft of a surgical instrument to align the shaft along thealignment axis.
 17. The surgical kit of claim 16, further comprising areamer orientable along the alignment axis using the orientation device.18. The surgical kit of claim 16, further comprising an implant inserterorientable along the alignment axis using the orientation device. 19.The surgical kit of claim 16, further comprising a plurality oforientation devices.
 20. The surgical kit of claim 19, wherein theorientation devices are disposable.
 21. The surgical kit of claim 16,wherein the orientation device includes a dome-shaped surface and abase, the orientation device including a leveling bubble.
 22. Thesurgical kit of claim 21, wherein the dome-shaped surface is transparentfor viewing the leveling bubble.
 23. The surgical kit of claim 21,further comprising a coupler for keying and coupling the base of theorientation device to an instrument shaft.
 24. The surgical kit of claim23, wherein the coupler is removable coupled to the base.
 25. Thesurgical kit of claim 16, further comprising a second patient-specificguide.
 26. The surgical kit of claim 25, wherein the secondpatient-specific guide is designed to fit to a different portion of thejoint surface.